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EWG's Tap Water Database — 2021 UPDATE

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Selenium

Waterworks District 7

Selenium is an essential element in diets. But too much selenium can decrease thyroid hormone production and cause hair loss, skin lesions and brittle fingernails.

 

40

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014N/A00N/A
2015N/A00N/A
2016ND200ND
2017N/A00N/A
2018N/A00N/A
2019ND200ND

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 30 ppb

The EWG Health Guideline of 30 ppb for selenium was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against hair loss and nail damage.

EPA Maximum Contaminant
Level (MCL) 50 ppb

The legal limit for selenium, established in 1991, was based on human epidemiological studies of populations exposed to naturally occurring selenium in drinking water. This limit does not include any additional consideration of children’s health.

ppb = parts per billion

All test results

Date Lab ID Result
2016-12-0535281860010ND
2016-12-0535281860001ND
2016-12-0535281860010ND
2016-12-0535281860009ND
2016-12-0535281860008ND
2016-12-0535281860007ND
2016-12-0535281860006ND
2016-12-0535281860005ND
2016-12-0535281860004ND
2016-12-0535281860003ND
2016-12-0535281860002ND
2016-12-0535281860001ND
2016-12-0535281860002ND
2016-12-0535281860003ND
2016-12-0535281860004ND
2016-12-0535281860005ND
2016-12-0535281860006ND
2016-12-0535281860007ND
2016-12-0535281860008ND
2016-12-0535281860009ND
2019-11-1935514133001ND
2019-11-1935514133010ND
2019-11-1935514133009ND
2019-11-1935514133008ND
2019-11-1935514133007ND
2019-11-1935514133006ND
2019-11-1935514133005ND
2019-11-1935514133004ND
2019-11-1935514133003ND
2019-11-1935514133002ND
2019-11-1935514133001ND
2019-11-1935514133010ND
2019-11-1935514133009ND
2019-11-1935514133008ND
2019-11-1935514133007ND
2019-11-1935514133006ND
2019-11-1935514133005ND
2019-11-1935514133004ND
2019-11-1935514133003ND
2019-11-1935514133002ND